Means for cold pressure welding



Sept. 2, 1952 A. B. SOWTER I 2,608,837

- MEANS FOR COLD PRESSURE WELDING Filed Feb. 4, 1950 FIG. 5.

INVENTOR ANTHONY BAGNOLQ SOWTER ATTORNEY Patented Sept. 2, 1952 3 2,608,887

: UNITED STATES PATENT MEANS FOR COLD PRESSURE WELDING I Anthony Bagnold Sowter, Wembley, England, as

signor to The General Electric Company Limited, London, England Application February 4, 1950, Serial No. 142,389

In Great Britain March 28, 1949 6Claims. (01. 78-89) I 1 i This invention relates to tools for cold pres- If a closure disc is to be welded into the bottom sure welding, more particularlyto the making of a tubular part provided with an inturned of cold weld connections of the type where a flange, the said toolor anvil will have f.- first member is to be joined to a flange or simicess into which the bottom of the tubular part -lar lateral projection of a second member. fits, a "pressure applying tool passing down in;-

In the welding together of aluminum, alumiside the tubular part. In this manner," b

num alloys and other metals capable of being tom of the tube will bercontaindby sfldafitil,

cold pressure welded, where a member is to be to substantially prevent distortion or splayin'g welded around or to the end of another part, out of metal beyond thecontour thereof, 1 particularly a tubular part, the member engag- 10 Where the outside of the flange radiused,

ingan inturned flange on the part andwelding the height of the recess should only f be] such pressure being applied across the superposed that thetop oi, the'recess is level with thetop member and flange, there is often the tendency of the radiused part so that, on 'welding, for the metal of the part to be forced or flow metal is as it were trapped at the tOHQfj-the in a direction away from the flange and so to recess to make removal of the weldedlpartf and produce a bump at the end of the part. Thus, member diificult. I g f V 4 where a closure disc is being welded to the bot- ,The invention may be applied particularlyjto tom of the wall of a can, the bottom being turned the manufacture of cans of circular section inwardly, the bottom of the wall tends.v to splay but it can also be applied to the manufacture out a certain extent on welding. of cans of other sections, such as, rectangular.

This is undesirable in certain cases partic- Where the wall of a can. is seam welded by cold ularly where a tubular part is seam welded and pressure welding, since splaying of metal is pre an object of the present invention is the provivented, there is no tendency for opening of the sion of a tool for cold pressure welding which seam when welding a closure disc in the bottom avoids this defect. f ofthe can. I a v The invention, both as to its further objects In carrying the invention into effect, accord.- and details will be better understood from the ing to one example of constructionv as shown following detailed description of a practical emin the drawing, a circular section can l0 has bodiment in connection with the accompanying a closure disc ll welded into its bottom ,by a drawing, forming part of this specification and tool in accordancewith the invention. Thecan wherein: is made from aluminium or other metal capable j vFigure 1 isa vertical cross section of a tool of cold pressure welding and the wall or cylinassembly for joining a bottom or end member drical part of the can is'advantageously made to an inturned flange of a tube by cold pressure by rolling a strip of aluminum around a mandrel welding in accordance with the invention; (see FigureZ) ofright circular section and'mab Figure 2 is a horizontal cross section showingja seam weld or lap joint by cold pres'sure ing a tool for producing the tube of Figure 1 welding. The} mandrel l2 itself may form an by cold pressure welding; I anvil cooperating with a shouldered cold pressure Figure 3 is a vertical cross sectional through welding tool or die l3 formed with a suitably a further tool assembly for joining the top to shaped flat welding tip H which makes the the tube shown in Figure 1 by cold pressure actual. weld upon application of suitablejpreswelding, to produce a sealed can or container; Sure in the direction indicated by-the win and the drawing. I F gures 4 and 5 are enlarged fractional views After seam welding, the excess metal'isicleaned showing a completed cold weld joint without or filed off at the seam. A small amount of ex}- and with the improvement of the invention, recess metal may be left on the insideof thewall,

spectively. particularly at the ends of theseam, in order Like reference characters identify like parts possibly t aid making a reliable weld-when the in the different views of the drawing. end closure discs are applied. r j; According to the present invention, the tool or One end of the wall, is then "turned over in} anvil upon which the inturned flange of the wardly to providea flange I5, the'outside of the part rests during welding is recessed, the wall bottom being suitably radiused as at IBQ The of the recess being arranged to prevent splayinside surface of the flange is then cleaned such ing out of metal of the part and to constrain as by scratch brushing to remove any oxide'film "the metal to flow, if at all, in the direction or other surface contamination from thd'sur in which the pressure for cold welding is face. The bottom of the wall is then set in 'a applied. recessed tool I! or anvil which exactly fits .or

3 conforms to said bottom, the height of d the re- 0855 being such that its top is just level with the end of the radiused part it of the flange IS. The anvil I! may be of mild steel and may be set in a press.

A closure disc H which just flts inside the wall ll! of the can also has its edge cleaned by scratch brushing or the like and is then laid down on the inside surface of the flange. pressure applying tool I2 is brought down into the inside of the wall ID of the can to cold weld the edge of the disc to the flange. This tool which may be the same mandrel or anvil used-- in producing the cylindrical part H) as described in connection with FigureZ}, should be a good sliding fit in the wall and consists of a member' of mild steel, circular in section, and having on its bottom an annular axially projecting flange or rib I8 whichforms the pressure applying means and which has a flat edge of the required width, about 1 times thercombined thicknessof the closure disc and flangei Radially inwards of the shoulder'is a circular projecting portion is which engages the closure disc but projects by] a smaller distance than does the in) [.8 .n o the bottom of the member :2. For this purpose, the bottom wall of the recess in the tool .or anvil I"! advantageously has a raised central portion I? of a height equal to the thickness of, the flange 15,. to. prevent distortion of the disc ll by the projection l9 during thewelding operation. In this manner the projecting portion 19 serves to limit and accurately'v control the percentage reduction during welding. The latter has been found critical in order to produce an eificient cold weld connection and amounts to a minimum of about 7Q%.Yof. the total thickness of the members H and lli in caseof aluminum.

.;.'I'he annular rib I8- engages the edge of the along its length. In other words, the recess in' the tool ll restricts and diverts the metal flow around the. bent l6 connecting. the flangeqlfi with the container wall H), in such a manner as to. substantially prevent outward splaying of said bent during welding. Instead of leaving excess metal on the inside of the wall to improve the weld at the seam, filler metal may be added there. r

Figures 4 and 5 show more clearly the completedscold weld joint obtained without and with the containing meansaccording. to the" invention. respectively. When using a flat anvil H, as shown in Figure 4, the metal of the lower flanged part I 6 of the can It is distorted or forced in. a direction away from the flange, as indicated by the arrow in the drawing, thus leave ing a bump or projection at the end of the can. Figure 5 shows the efiect of the recessed tool oranvil according to the invention by restraining the flow of the metal in a direction substantially parallel to the application of the welding pressure, as indicated by the arrow, thus preventing distorting or splaying out of the lower'end of the can. beyond the contour there- Of. I

After making the weld, the inner tool is removed, the welded wall and disc removed from the recess in the anvil H. The top of the wall 18 is turned outwardly to form a flange 20 as shown in Figure 3. A further closure disc 2! with a filling hole is laid .onthis flange after the flange and edge of the disc have been cleaned by scratch-brushing or the like and then the disc welded to the flange by means of a hollow cylindrical tool 22 which passes down over the bottom of thecan and applies welding pressure against a flat anvil 24. This cylindrical tool has an annular welding rib 25 with a flat tip and,-radially outwards of said rib, a surface or shoulder 26 which projects a suflicient distance beyond the rib to control and limit the percentage reduction of the total thickness of the flange 28 and disc 24 on welding by engaging the flat anvil 24. The hollow cylindrical tool 22 is then withdrawn and the completed can removed from the press. 7

As will be uhderstoodthe special ring-shaped welding tool or die l2 may be used for cold welding together any other'pair or superposed'mem bers such as. sheets, discs, rings or the like, with the rib l8 serving to define the pressure applying or operative welding area, in the manner described, and with the projecting portion [9. act ing as an abutment or limit to control the percentage reduction of the totalLWork thickness'at the welding area. In place of the annular shape as shown, the tool may be designedjfor effectinga cold weld along any other closed or endless weld line or trace, such as for producing ellipsoidal, square or rectangular cold weld con} nections, depending upon the construction and shape of the members to be welded together..

While there has been disclosed and described be evident .from the foregoing that changes in the size, shape and arrangement of parts, as well as the substitution of equivalent elements and stepsfor those described herein, may be made without departing from the scope andspirit of the invention as set forth in the appended claims. Thus, it will be understood. that the invention has general use and application wherever one member is to be cold welded close to and onto a flange or other lateral projection of a second member and where the danger 'exists of the first member being distorted or splayed as a result of the cold welding operation. By the use of a specially designed recessed tool or containing means according to the present invention, this difficulty is greatly minimized or prevented, independently of the remaining part or shape of the members being joined. The specification and drawing are accordingly to be regarded in an illustrative rather than in a limiting sense.

I claim: v

1. Pressure welding apparatus for lap joining a first member to an angular flange of a second member, said members consisting of pressure weldable metal, comprising first pressure welding tool means having a recess conforming to the bent formed by said flange and second member, to receive and contain said bent. with said flange resting upon the bottom of said'recess, and a cooperating welding tool for pressure welding said first member to said flange, said recess substantially restricting and divert.- ing metal flow around said bent, to prevent outward splaying thereof during welding.

2. Pressure welding apparatus for lap joining a, first member to an angular flange of asecond member, said members consisting of pressure weldable metal and said flange being connected with said second member through a radiused bent, comprising first pressure welding tool means having a recess conforming to said bent, to receive and contain said bent with said flange resting upon the bottom of said recess, and a cooperating welding tool for pressure welding said first member to said flange, said recess substantially restricting and diverting metal flow around said bent, to prevent outward splaying thereof at welding.

3. Pressure welding apparatus for lap joining a closure disc to the inturned flange provided at the end of a tubular member, said disc and member consisting of pressure weldable metal, comprising first pressure welding tool means having a recess conforming to the bent formed by said flange and member, to receive and contain said bent with said flange resting upon the bottom of said recess, and a cylindrical cooperating pressure tool arranged to slide within said tube and havn ga projecting annular welding rib, for pressure welding said disc to said flange, said recess substantially restricting and diverting metal flow around said bent, to prevent outward splaying thereof during welding.

4. Pressure welding apparatus for lap joining a closure disc to the inturned flange provided at the end of a tubular member, said disc and member consisting of pressure weldable metal and said flange and member forming a, radiused bent, comprising first pressure welding tool means having a recess conforming to said bent, to receive and contain said bent with said flange resting upon the bottom of said recess, and a cylindrical cooperating pressure tool arranged to slide within said tube and having a projecting annular welding rib, for pressure welding said disc to said flange, said recess substantially restricting 6 and diverting metal flow around said bent, to prevent outward splaying thereof during welding. 5. Pressure welding apparatus for lap joining a closure member to the inturned flange provided at the edge of a container wall forming a bent therewith, said member and container consisting of pressure weldable metal, comprising first pressure welding tool means having a recess conforming to said bent, to receive and contain said bent with said flange resting upon the bottom of said recess, and a cooperating pressure tool arranged to slide within said container and having a projecting welding rib for pressure welding said member to said flange, said recess substantially restricting and diverting metal flow around said bent, to prevent outward splaying thereof during welding.

6. Pressure welding apparatus for lap joining a closure member to the inturned flange provided at the edge of a, containerwall, said member and container consisting of pressure weldable metal and said wall and flange forming a radiused bent, comprising first welding tool means having a recess conforming to said bent, to receive and contain said bent with said flange resting upon the bottom of said recess, and a cooperating pressure tool arranged to slide within said container and having a projecting welding rib for pressure welding said flange to said member, said recess substantially restricting and diverting metal flow around said bent, to prevent outward splaying thereof during welding.

ANTHONY BAGNOLD SOWTER.

REFERENCES CITED UNITED STATES PATENTS Name Date Sowter alumna. Sept. 12, 1950 Number 

